Eubulus parochus (Herbst)

Anderson, Robert S., 2008, A Review Of The Genus Eubulus Kirsch 1869 In The United States And Canada (Curculionidae: Cryptorhynchinae), The Coleopterists Bulletin 62 (2), pp. 287-296 : 289-292

Eubulus parochus (Herbst)

( Figures 1–2 , 7–8 , 14 )

Curculio parochus Herbst 1797:55 .

Cryptorhynchus luctuosus Boheman 1837:146 .

Eubulus parochus ; Champion 1905:581.

Rhyssomatus beutenmuelleri Van Dyke 1930: 161 .

Taxonomic notes. Herbst and Boheman types were not examined. LeConte (1876:251) gives C. luctuosus Boheman and C. misellus Boheman as junior synonyms of C. bisignatus Say. Subsequently, Champion (1905:581) , states that ‘‘ C. luctuosus Boh , of which there is a specimen labeled ‘‘Mex’’ (a locality requiring confirmation) in Dr. Sharp’s collection seems to be synonymous with E. parochus Say , and not with E. bisignatus as quoted by LeConte.’’ O’Brien and Wibmer (1982:156) follow Champion and list Cryptorhynchus ‘‘? luctuosus ’’ Boheman as a junior synonym of E. parochus (but do not indicate why they used the ‘‘?’’ prior to the name). Anderson (1984) placed Rhyssomatus beutenmuelleri Van Dyke as a junior synonym of E. parochus .

There are five specimens in the LeConte Collection (MCZC). Two of these have pink circles (5 Vermont, New Hampshire, Massachusetts), one has a green diamond, and two are labeled ‘‘D.C.’’. All are Eubulus parochus (Herbst) . In the Horn Collection (MCZC) there are four Eubulus parochus labeled ‘‘CAN’’ and two Eubulus bisignatus labeled ‘‘PA’’.

Based on specimens examined by me, O’Brien and Wibmer (1982, 1984) appear to have mistakenly identified E. parochus as E. obliquus . Similarly, they identified larger E. bisignatus as E. parochus . This misidentification plus the discovery of a second species mixed with E. bisignatus in nearly all collections I have examined means that the distributions of E. bisignatus , E. parochus and Cryptorhynchus obliquus as given in O’Brien and Wibmer (1982) are either incomplete or incorrect. Consequently, the concerns raised by Halik & Bergdahl (2006) that the distribution of E. parochus extends beyond that of its sole known host, Juglans cinerea Linnaeus , butternut, are unnecessary. Records of E. parochus as presented here ( Fig. 14 ) do not extend beyond the range of butternut.

Diagnosis. Body size 4.8–6.5 mm ( Figs. 1–2 ). Head with eyes separated by almost width of base of rostrum in frontal view; area above each eye with welldeveloped oblique subcarinate ridge; frons foveate; femora each with two distinct teeth on inner margin, basal (proximal) tooth low and rounded (teeth broadly joined by poorly developed flange in some specimens). Aedeagus ( Fig. 8 ). Tergite VIII of female ( Fig. 7 ).

Most individuals of Eubulus parochus are easily recognized by their larger size but small specimens are difficult to separate from larger E. bisignatus .

Biology. A detailed study of the natural history, development and associations with fungi (butternut canker disease) on butternut, has been carried out by Halik & Bergdahl (2002, 2006) in Vermont. Adults are commonly collected on freshly downed limbs or small branches of butternut. Larvae mine beneath the bark in the outer cambium and sapwood. Adults appear to be casual vectors of pathogenic fungi. Museum specimens from Ontario and Indiana were also collected on butternut .

Distribution. Figure 14 . This species is found in the northeastern United States and adjacent Canada. State records are CT, IL, IN, KY, MD, MA, MI, NJ, NY, NC, PA, TN, VT, VA, WV; provincial records are NB, ON, PQ.

Figures

Figs. 1–6. Dorsal and lateral habitus of Eubulus species. 1, 2) Eubulus parochus; 3, 4) Eubulus bisignatus; 5, 6) Eubulus obliquefasciatus. Scale bar 5 1 mm.

Figs. 7–13. 7) Tergite VIII of female E. parochus. Scale bar 5 0.2 mm; 8) Aedeagus of male E. parochus. Scale bar 5 0.5 mm; 9) Tergite VIII of female E. bisignatus. Scale bar 5 0.1 mm; 10) Aedeagus of male E. bisignatus. Scale bar 5 0.5 mm; 11) Ventrite 5 of male E. obliquefasciatus. Scale bar 5 0.25 mm; 12) Tergite VIII of female E. obliquefasciatus. Scale bar 5 0.1 mm; 13) Aedeagus of male E. obliquefasciatus. Scale bar 5 0.25 mm.

Figs. 14–16. Maps of distribution of Eubulus species by state and province. 14) E. parochus; 15) E. obliquefasciatus; 16) E. bisignatus.